Subject: [RFC v02 04/15] dmaengine: edma: Add support for DMA filter mapping to slave devices

From: [email-masked] (Vinod Koul)
Date: Tue, 1 Dec 2015 22:52:12 +0530

On Mon, Nov 30, 2015 at 03:45:34PM +0200, Peter Ujfalusi wrote:
> Add support for providing device to filter_fn mapping so client drivers
> can switch to use the dma_request_chan() API.

Any reason why we dont want to go with DT based only for edma here?

> 
> Signed-off-by: Peter Ujfalusi <[email-masked]>
> ---
>  drivers/dma/edma.c                 | 24 ++++++++++++++++++++++++
>  include/linux/platform_data/edma.h |  5 +++++
>  2 files changed, 29 insertions(+)
> 
> diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c
> index 0675e268d577..386f8c9bd606 100644
> --- a/drivers/dma/edma.c
> +++ b/drivers/dma/edma.c
> @@ -2098,6 +2098,8 @@ static struct dma_chan *of_edma_xlate(struct of_phandle_args *dma_spec,
>  }
>  #endif
>  
> +static bool edma_filter_for_map(struct dma_chan *chan, void *param);
> +
>  static int edma_probe(struct platform_device *pdev)
>  {
>  	struct edma_soc_info	*info = pdev->dev.platform_data;
> @@ -2297,6 +2299,12 @@ static int edma_probe(struct platform_device *pdev)
>  		edma_set_chmap(&ecc->slave_chans[i], ecc->dummy_slot);
>  	}
>  
> +	if (info->filter_map) {
> +		ecc->dma_slave.filter_map.map = info->filter_map;
> +		ecc->dma_slave.filter_map.mapcnt = info->filtercnt;
> +		ecc->dma_slave.filter_map.filter_fn = edma_filter_for_map;
> +	}
> +
>  	ret = dma_async_device_register(&ecc->dma_slave);
>  	if (ret) {
>  		dev_err(dev, "slave ddev registration failed (%d)\n", ret);
> @@ -2428,6 +2436,22 @@ bool edma_filter_fn(struct dma_chan *chan, void *param)
>  }
>  EXPORT_SYMBOL(edma_filter_fn);
>  
> +static bool edma_filter_for_map(struct dma_chan *chan, void *param)
> +{
> +	bool match = false;
> +
> +	if (chan->device->dev->driver == &edma_driver.driver) {
> +		struct edma_chan *echan = to_edma_chan(chan);
> +		unsigned ch_req = (unsigned)param;
> +		if (ch_req == echan->ch_num) {
> +			/* The channel is going to be used as HW synchronized */
> +			echan->hw_triggered = true;
> +			match = true;
> +		}
> +	}
> +	return match;
> +}
> +
>  static int edma_init(void)
>  {
>  	int ret;
> diff --git a/include/linux/platform_data/edma.h b/include/linux/platform_data/edma.h
> index e2878baeb90e..117a36d63840 100644
> --- a/include/linux/platform_data/edma.h
> +++ b/include/linux/platform_data/edma.h
> @@ -59,6 +59,8 @@ struct edma_rsv_info {
>  	const s16	(*rsv_slots)[2];
>  };
>  
> +struct dma_filter_map;
> +
>  /* platform_data for EDMA driver */
>  struct edma_soc_info {
>  	/*
> @@ -76,6 +78,9 @@ struct edma_soc_info {
>  
>  	s8	(*queue_priority_mapping)[2];
>  	const s16	(*xbar_chans)[2];
> +
> +	struct dma_filter_map *filter_map;
> +	int filtercnt;
>  };
>  
>  #endif
> -- 
> 2.6.3
> 

-- 
~Vinod